MONTPELIER — Six elderly Massachusetts women are scheduled to go on trial next week on charges they chained themselves to the gate at the Vermont Yankee nuclear power plant two days after the state was hammered by the remnants of Hurricane Irene.

The women, all members of the Shut It Down Affinity Group, traveled to the plant gate in Vernon on Aug. 30, 2011, used a chain and padlock to lock the entrance gate and chained themselves to the fence, members of the group said.

It was one of about 22 protests the group has mounted against the reactor’s continued operation in recent years. There have been five similar protests since the one that triggered the trespass charges on which the women are to be tried next week.

The six were identified as 93-year-old Frances Crowe, 82-year-old Nancy First and 68-year-old Patricia “Paki” Wieland, all of Northampton, 73-year-old Hattie Nestel, of Athol, 69-year-old Ellen Graves, of West Springfield, and Mary Kehler, also known as Betsey Corner, 64, of Colrain.

Neither Windham County State’s Attorney Tracy Kelly Shriver, nor her deputy, Steven Brown, who is handling the case, would say why that particular protest was selected from nearly two dozen similar events in recent years as the one that would produce charges.

Two of the protesters, Crowe and Nestel, said there was nothing unusual about their behavior at the plant gate compared with other protests. But they said Vernon police Chief Mary Beth Hebert expressed displeasure to them that they would hold a protest two days after Irene caused widespread flooding in southern Vermont, spreading public safety personnel thin.

Calls to Hebert’s office on Wednesday seeking comment were not immediately returned.

Shriver and Brown refused to say whether the proximity to the storm-related emergency is what prompted the trespass charges against the women. The charges carry a potential penalty of three months in jail and a $500 fine for each defendant.

Crowe said she had had a long career in such protests and previously served time in jail. She spent three months in jail in Cranston, R.I., after being arrested during a protest against nuclear weapons in that state, she said.

She said she was pleased her Vermont activities were drawing a stiffer reaction from authorities.

“We are very honored. They’re finally taking us seriously and they’re taking us to trial,” Crowe said.

Asked how many time she had been arrested in such protests, she pointed to the fact that war, nuclear weapons and nuclear power plants continue to exist. “Not enough,” she said. “I don’t know. I don’t count. But I know I haven’t achieved what I’m trying to achieve.”